Improvement in molds for casting bobbins



UNITED" S'rn'rns MARTIAL DIMOOK, OF NEWARK, NEW JERSEY, AS SIGNOR TO THE CLARK THREAD COMPANY, OF SAME PLACE.

IMPROVEMENT IN MOLDS FOR CASTING BOBBINS.

Specification forming part of Letters Patent No. 159,397, dated February 2, 1875; application filed August 18, 1873.

To all whom it may concern:

Be it known that I, MARTIAL DIMocK, of the city of Newark, county of Essex and State of New Jersey, have invented certain Improvements in Mold for Casting Bobbins for Sewing-Machines, of which the following is a specification:

This invention consists of a mold for casting bobbins constructed of four parts pivoted to a shank or foundation, and combining therewith a handle provided with a cam at one end and with a spring, in such a manner that when said handle is pushed in the cam is caused to advance and force apart the pivoted parts of the mold to deliver the bobbin, which is cast complete and ready for use, the action of the spring being to retract the handle in order to allow the parts of the mold to come together for casting another bobbin, as hereinafter described.

Figure 1 is a sectional view of a mold for casting said bobbins, and it shows one of the bobbins in the position in the mold, and the sprue attached, as it would appear when the process of casting is completed and just before the mold is opened. Fig. 2 is a sectional view of the mold through the center and at a right angle to the view at Fig. 1, or transversely with the axis of the bobbin. Fig. 3 shows the bobbin complete after being cast and the sprue broken on.

It is well known that bobbins for sewingmachines have been formed of various materials, but the labor expended in the manufacture has always been an objectionable feature in the production of such articles; and to overcome this objection a mold, as at A, formed of any suitable material, as brass, is provided to operate similarly to the mold used in the process of casting types for printing.

In the illustration here given the mold is divided into four parts, each member of which is hinged or pivoted, as at B, to a shank, which serves as a foundation to hold the parts together or in working position, and also allows the several parts to be opened or separated from around the bobbin when cast. Said shank, as at C, also serves to connect the mold with a handle, as at D, or with a machine, if one beused, as in the process of type-casting. The said four parts of the mold have formed upon their inner faces suitable are cast in a recess formed in a solid portion of the mold, and therefore they cannot have a rib or fin on them, as would be the case if the mold parted from end to end of the bobbin.

The gate is shown at F, and is made so that when the metal enters the mold it is very thin, and is also on the portion of the bobbin that is covered by the thread; consequently, when it is broken 0E, any little degree of roughness left is not objectionable.

These several parts of the mold may be held together by a band of metal around them, or in any other convenient manner, in which condition the mold is ready for being filled with the melted metal.

It is proposed to use the ordinary typemetal, orQsomething having substantially the same properties, as melting at a low temperature, and therefore cooling'quickly, and at the same time being capable of receiving a smooth surface when cast, and also comparatively inexpensive 5 and said metal may be injected into the mold by any suitable apparatus for such purposes. After the mold is filled the band around the parts may be removed-that is, if one be used-and the several parts may be driven or forced open by striking upon the handle at D, which will forcea rod, R, (connecting the handle I) with the mold,) upward, and thereby drive or force the crosspiece, as

at M, on the end of the rod up against the inshank G,or lower end, than those on the edges consequently the sides will be driven 05 from the bobbin first, or while the ends or tips are still at rest in their respective sockets, and then, after the sides are separated, the crosspiece M acts upon the edges to free the ends finishing would make them too expensive for the short time they are intended to be used, say until fifty or seventy-five yards of thread are used in sewing; and it is also well known that said bobbins had 110 tips or centers to hold them in the shuttle of a sewing-machine.

I therefore claim- In combination with a mold, as described, a handle, D, cam M, spring R, and spring N, as and for the purposes set forth.

MARTIAL DIMOGK. Witnesses:

CHAS. H. LEONARD, PHILIP OREILLY. 

